Why do men say 'I do'?

Advice Goddess

A female friend of mine wanted to get married, but her boyfriend was resistant. He'd been married before, with disastrous results. He eventually married her — not because he wanted to be married but because it meant so much to her. Initially, she felt bad about this. She had to give up her romantic dream of getting married because somebody would want to be tied to her forever. Do men just marry women to make us happy?— Wondering Woman

Picture a zookeeper coming in in the morning and going, "Crap — we've got a new giraffe. How did he get in here?"

On one level, a man pining for a life in sexual captivity makes about as much sense as a wild animal breaking into a zoo. Evolutionary psychologists David Buss and David Schmitt note that we humans evolved to choose between two different sexual strategies — short-term and long-term. Women typically benefit more from a "long-term sexual strategy" — a commitment model, i.e., getting men to stick around to invest in their children. Men often benefit more from a "short-term sexual strategy" — a lack-of-commitment model, i.e., sticking it into a long line of sexfriends. That's because a man can have sex with thousands of women and never end up pregnant with something that needs to be fed and sent to hipster day care.

Though a man gets more shots to pass on his genes with the short-term "I love a parade!" approach, it's sometimes more advantageous for him to opt for a long-term strategy. It's a huge time-, energy- and resource-suck to perpetually be on the hunt. Also, Buss explains, because "highly desirable women" can hold out for commitment, men can get a much better woman if they're willing to go for a long-term thing (buying the relationship stroganoff instead of living off the free samples in the supermarket).

Whether to commit generally doesn't play out in men's heads in such clear cost-benefit terms — like calculations on whether to go all in on pork futures. It's emotion that pushes them toward commitment — loving a woman who happens to insist on a commitment and wanting to make her happy. Economist Robert H. Frank calls love "a solution to the commitment problem." Mushywushy feelings are what keep you with that special someone — instead of running off the moment somebody who's objectively a better deal moves in next door or your beloved is tossing her cookies on the side of the road: "Bye, hon ... hope somebody nice comes along to hold your hair back!"

So a man's being willing to officially take his penis off the market — even if he isn't particularly hot on the idea of marriage — is a really big deal. There are two major reasons you spend the rest of your life with one person: Either you realize you love them more than you love your freedom or you're serving a sentence for a string of really bad felonies.

In thickness and health

My wife isn't smart. She also doesn't read books or newspapers or know anything about current events or politics. I knew that when I married her, but we were both kids, and I thought it was kinda sweet and funny. Fifteen years later, it bothers and embarrasses me. I still love her, but I'm depressed by the idea of spending the rest of my life with someone who can't share some of what I see as life's basic pleasures. —Hating Myself for Sounding Snobby

It's something of an attraction killer when you look deep into a woman's eyes — and feel pretty sure you can see clear out the back of her head.

Yes, 15 years ago, you pledged to spend forever with this woman — surely intending to follow through, despite how she probably makes major life decisions by consulting fortune cookies. The truth is, we can lack foresight when we're younger. (As late as eighth grade, I announced to my parents with great gravitas: "Roller skating is my life!")

Though you care about her, what you're missing — being similar in essential areas — is called "assortative mating." Psychologist Michelle Shiota notes that "studies have repeatedly found that similarity between romantic partners in domains such as socioeconomic status, educational background, age, ethnicity, religion, physical attractiveness, intelligence, attitudes and values predicts higher levels of marital satisfaction and lower likelihood of separation and divorce."

Sure, you could focus on what you love about her and try to get your intellectual needs met elsewhere. However, if what makes you feel alive and connected to somebody is engaging intellectually, this might just be a bridge too far — being with someone who believes the Electoral College is where your 18-year-old niece is going next fall to study bioengineering.